ER-4p resistance converter?

I've been reading about mods that supposedly increase SQ of the ER4P by introducing a resistor to the input. I am very confused as to how that improves sound quality.

If anything it reduces transient response, and I feel like it would resist different frequencies to differing degrees.

I understand the concept of higher impedance headphones, which is a product of lighter, less conductive drivers, but how would increasing the resistance of an intrinsically ~32 ohm driver improve the sound at all?

The mod is a 75 ohm resister to turn the er4p into the er4s. Etymotic released the er4p as a lower-impedance version of the 4s, which (the 4s) they deemed more accurate to their reference curve. By adding a resistor you will get a notable bump in the upper mids and a slight decrease in the lower mids and bass. Try it and see which one you prefer.

so what im getting is that this is just an add-on that happens to bring up impedance? That makes more sense. It sounds completely rediculous for someone to artificially bring up impedance for the sake of sound quality, after all, the driver's still receiving the same voltage.